So I get in my truck today to drive it and when I fire it up I notice the check engine light is on. Being in a hurry I decided to drive it anyway, so I headed up the road and noticed it was running really rough and had horrible acceleration. I also noticed the check engine light started blinking.

So I turned around and headed back home. When I checked the CEL for a code I got P0203 which after looking it up I found means there is a problem on cylinder #3 with the injector or the injector harness.

Is this common on these trucks? If I don't see any issues in the wiring should I replace the injector? How hard are the injectors to replace? I've just never had a reason to mess with them before. Also, how much do they run?

My other question is, could it be something else? I read a post on another forum in a later year truck saying it could also be a broken valve spring causing this. This peaked my curiosity as I have a lifter or something that's leaking down as when it's cold out in the winter and I fire the truck up after it's been sitting, it makes a loud knocking sound until the oil pressure builds up. It still runs perfect, or has until now, and since it's gotten hot out, it hasn't made that sound, so I'm pretty sure it's a lifter leaking down. Could this have something to do with it, or is it most likely a failed injector?

 

Swap the injector and see if the code moves to another cylinder. If it does, suspect injector. If not, suspect the cylinder/injector wire itself.

 

do you have the red injectors? if so, I have a few laying around that will save you $75 or so..

and, uh, what Aim said..

while removing and installing, don't hesitate to lube both the O ring and the bung.. a light coat of clean oil does the trick.. don't twist them in, they go straight in.. you can twist them out, but don't expect to reuse the O rings afterward.. they are fragile.. if you crease, crush, or tear one- the least of your problems will be a P0203.. you'll be squirting gas around the engine bay, and it WILL find a spark as if it's on a mission.. not cool, ya know?

 

Replace the o-rings -- PERIOD. Cheap insurance.

 

yup. silly not to. a card of 16 (one bank) of them is like $1.50

 

Thanks for the advice guys. I'm for sure going to replace the O rings as I don't want them to leak. It's going to be at least tomorrow afternoon if not Sunday before I get a chance to even mess with this thing much, but I will try changing the injectors and see if the problem follows it.

Now, does anyone have any advice on how to remove and install the injectors? It's not something I'd think would be super hard, but honestly, I've never done it before. Do you just unbolt the injector rail and the pull the injector out? Or are they bolted in or what? Is there a particular way they have to go in?

This really doesn't seem like it's something that could be that hard, but like I said I've just never really even looked at it so have never had to worry how it worked.

 

Not sure yet, but if I do and it turns out to be the injector I will be sending you a pm.

 

I'll likely get torched for saying this, but: It's been my experience, that removing an injector requires some effort- not manilla gorilla effort, but don't be shy either..

I've even used a wrench to pry them out.. I've even done it prying against the fuel rail.. I wouldn't rec that though.. I wouldn't even consider it if your rail is plastic..

putting them back in is the frustrating part.. the trick is to use oil on both the injector O ring, as well as the interior of the bung.. get a good angle, get a good position, and press that bad bear in with increasing pressure until it seats.. you'll KNOW when it seats.. if there is any question, it likely isn't..

if you have it partially in, you can actually use your fuel rail's bolts to seat it..

also, some will want to stay in the rail, while others want to stay in the manifold.. use your clips as a bit of encouragement over which way you wanna go.. personally, I rec you pull them off with the rail.. especially if your rail is metal.. (this is me going back and forth on whether or not to lever that thing) .. if you leave the clips on the rail, all you gotta do is pull the anchor bolts and gently pry the back up (using the keg) and shift to the front.. 1/4 way on the back, 1/2 way on the front.. then 3/4 on the back, fully out on the front- pull the back up the rest of the way... sorta gently rock it out, using a lever of some sort between the rail and the manifold..

going back in is tricky.. if your rail is metal, lube the o rings, and the bungs.. align it best you can, press firmly with increasing pressure on each end of the rail at the same time.. get it near seated, or seated.. if nearly seated, use your anchor bolts to press them in the rest of the way..


once they are in there: once you feel them seat, and whether the rail is on them or not- ONLY when they are seated.. spin them on their axis a bit back and forth.. this kinda promotes aligning the O rings, if they are unevenly pressed in, and puts them back in the channel on the injector they are supposed to be in.. pull slightly up on each injector to 'roll' the O ring to the bottom of their channel.. then tighten your anchor bolts for good..

when you are finished.. have a friend turn the ignition over whilst you watch the injector/rail and injector/bung junction.. look for leaks.. have them turn the engine over.. keep looking.. if your okay for the first five or so minutes of run time, you're likely okay for good as far as leaks go..


I've made it sound more difficult than it is.. but that is just about all there is to it.. just make sure and lube the O rings and the bungs- that, if anything, is the key..

edited to add: if your paws are big enough, stretch one hand from the base of your little finger (end of rail) to the first joint of your thumb.. other hand opposite.. when pressing the rail/injectors in as a complete unit.. you don't want too much pressure in one place.. spread it out best you can..

 

Yes you unbolt the rail and pull upward. They can be boogers to get out if they've been in there a long time. Do it after the engine has sat for several hours so the fuel pressure will be low. You're gonna spill some, but you don't want to spray it everywhere.

Before you uninstall them, note how deep they are installed into the intake bungs, maybe even mark it with a sharpie. You want to make sure you get them back in there that deep, or they can pop out and leak fuel. You can imagine how that would end up on a hot exhaust manifold or header.

Try a little rocking front to back and some lube in the injector bungs before you start pulling up.

There are little clips at the top that hold the injector to the rail, you can pop them off by prying gently with a standard screwdriver going straight out and away from the injector rail. Don't lose them, they are a bit springy and like to go flying if you bubba it. Then twist and pull the injector to get it to come off the rail. Re-installation has to be the correct height or the clip won't fit back in the injector groove, so that part is pretty hard to mess up.

I'd swap the number 3 injector with number 1 to make it easiest to work on.

 

I've never had a problem removing injectors. You all must be girly men.